Ernst Grahn

Ernst Grahn (born March 15, 1836 in Hanover , † July 25, 1906 in Waldhausen near Hanover) was a German hydraulic engineer . He is considered one of the most important water economists of the 19th century.

Life

Ernst Grahn began studying iron engineering at the Hanover Polytechnic in 1852 . In the same year he became a member of the Slesvico-Holsatia country team, later the Slesvico-Holsatia Corps . In 1860 he passed the state examination with excellent good . After completing his studies, he took up his first job as an engineer at the Hanoverian iron foundry, where he planned gas and water works . In 1862 he moved to Braunschweig to plan a new waterworks . In 1863 he went to Krupp in Essen , where he managed the company's own gas and water supply systems. Under his leadership, gas production increased twenty-fold over the next twenty years and the central water supply increased to a daily output of 40,000 cubic meters. In addition, he carried out basic research on the processes in the retort furnace . His social commitment was aimed at the welfare of the workers he employed, whom he encouraged to take out life insurance policies to support their families . He also founded public libraries .

In 1883 he settled in Koblenz as a consulting engineer , where he dealt with the planning and construction of gas and water supply systems, including the planning and construction management of the Koblenz-Oberwerth waterworks and the second gas works in Mainz . Over 70 cities at home and abroad, including Vienna , Budapest , Trieste and Szeged , were among his clients. In 1889 he moved from Koblenz to Detmold and in 1895 to Hanover.

In 1865 he was accepted into the association of gas specialists , in which he is actively involved. Here he campaigned for the expansion of the association's purpose to include the water subject, which he succeeded in 1869. Since then the association has been called the German Association for Gas and Water Experts (DVGW). From 1879 to 1880 and from 1883 to 1884 he was chairman of the DVGW.

For Hamburg's drinking water supply from the Elbe , which was realized in 1877, he made important contributions with regard to the technical requirements, namely a uniform filter system with slow seepage and clarification basins that are high enough to be able to completely empty and clean them at low tide. He was an advocate for assessing the quality of drinking water regardless of its origin. Rather, he used epidemiological, chemical and microbiological investigation methods, even if he was initially unable to set any binding limit values ​​for safety, but recognized the absence of faeces as essential. He produced previously unknown statistics that provided information about the water supply in German, Austrian and Swiss cities. One of his last activities was the preparation of reports on the origin, course and cause of the typhus epidemic in Gelsenkirchen of 1901, which he completed in 1904. He was unable to complete his last job, to collect technical masterpieces for the water supply department of the Deutsches Museum in Munich . A few months before his death, on his 70th birthday, he had received high honors from all over the world.

Awards

• In 1900 he was awarded the Bunsen-Pettenkofer Honor Roll of the DVGW. This award is the highest recognition of extraordinary commitment in the gas and water sector.

• In 1857 Slesvico-Holsatia made him an honorary boy.

Fonts

Gas supply:

• Establishment of experimental gas stations , 1870
• Mechanical pulling and loading of the retorts , 1875, 1876
• Machines for pulling and loading the retorts , 1879, 1881
• Heating of retorts with coal gas , 1881
• England and Wales gas plants compared to those in Germany , 1883
• Furnaces with inclined retorts , 1895
• Vienna gas question , 1896, 1898
• Retort Furnaces , 1897

Water supply:

• Water Supply Statistics in English Cities , 1874
• Spring water and river water supply , 1875
• Great Britain's drinking water supply , 1876
• Legitimate City Water Claims , 1876
• Statistics of the water supply in Germany, German-Austria and Switzerland , 1876, 1877
• Prague's water supply , 1877
• Clarification and filtration of the water , 1877
• Water supply to Paris , 1878
• Vienna water supply , 1878
• The pressure required in water pipes with regard to fire extinguishing purposes , 1885
• The necessary pressure in water pipes with regard to fire extinguishing , 1886
• Assessment of central water supply systems from the hygienic and bacteriological point of view , 1888
• Filter systems for municipal water supplies , 1890
• Bacteriological water investigation and principles for investigation , 1893
• Principles for the Purification of Surface Water by Sand Filtration at the Time of Cholera , 1894
• Current state of sand filtration for municipal water supplies , 1895
• The water supply in the German Empire and some neighboring countries , 2 volumes, Berlin, 1898–1902
• The municipal waterworks . In: R. Wuttke (ed.): The German cities. Described based on the results of the first German city exhibition in Dresden , 2 volumes, Leipzig, 1904, volume 1, pp. 301–344

literature

• Bernd Gockel: Ernst Grahn - a man looking to the future . In: GWF , Volume 110, Issue 10, March 7, 1969, pp. 254-257
• Paul-Gerhard Franke, Adolf Kleinschroth: Brief Biographies Hydraulics and Hydraulic Engineering: Personalities from German-speaking countries , Munich, 1991
• Anne I. Hardy: Drinking water theory and river pollution in the 19th century . In: Without water there is no medicinal and cultural aspects of the use of water , Munich, 2005, ISBN 3-515-08785-0

Individual evidence

1. ↑ Corps Slesvico-Holsatia, Corpsliste , winter semester 1981/82, p. 12, no. 026
2. ↑ The chairmen or presidents of the DVGW since 1859 ( memento of the original from March 1, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
3. ↑ The new filter systems for Hamburg's water supply. In: Centralblatt der Bauverwaltung, Volume 13, No. 8 (February 25, 1893), p. 89 f.
4. ↑ Owner of the Bunsen-Pettenkofer roll of honor ( Memento of the original from March 31, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
5. ↑ History of the DVGW, 1900 ( Memento of the original from September 13, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.